Patent GB-139773-A (GB)
Title: Improvements in photography
IPC: G03B27/475
Filed: 1920-03-01
Abstract: 139.773. Clark, E. W. Feb. 25, 1919, [Convention date]. Kinematograph apparatus. - Kinematograph films having images of standard size and arrangement are printed from negative films of standard size, but having images turned through a rightangle from the usual position, and of double the usual area. The printing apparatus comprises a lamp house L carrying a condenser 35, spools and intermittent pin-feed mechanism for feeding the negative film horizontally past a gate aperture 143, similar mechanism for feeding the sensitive film vertically past a gate aperture 183, and a projection lens 263 and shutter 251. Means for driving the spools and mechanisms by motor or hand, and light-tight magazines 155, 157 carrying the sensitive film and having light-tight connexion with a casing P, are provided. The lamp house has an adjustable electric lamp 13, air inlets and outlets 27, 29 provided with baffle plates, and a casing 5 within which the condenser is adjustable. A light-tight hood 3 extends from the condenser case to the negative gate. A motor is geared to a main drive shaft S which is provided. with a hand crank. From the shaft S each takeup spool is driven through friction gearing, and also each feed mechanism. The feed mechanism for the negative film comprises a vertical shaft 95, Figs. 12 and 13, driven by toothed gears 92, 93 and having a crank disk 97 and a cam disk 99. A connecting rod 107, adjustable in length, extends betiween a pin 105 on the disk 97 and a slidable carriage 111, and slides the carriage along guides 112 to feed the film. Feed pins 85, Fig. 14, project through openings in the carriage 111 to engage the film, and are mounted on a cross carriage 113 sliding on a rod 115 carried by pivoted arms 119, 121. The arm 121 is a bellcrank lever having an arm 125 pivoted to a link 127 guided by a slot 129 and carrying a roller 101. The cam disk has a cam slot 103 on its edge so shaped that, through the linkage described above, the pins are withdrawn from the sprocket holes at the end of each feed movement and projected into them at the beginning of the next. Variation in the length of the feed can be effected by changing the crank disk 106 or adjusting its throw. The film gate 135 is hinged and held by a catch, and has a glass pressure-plate 141, pressed against the aperture plate 83 by leaf springs 144, and a spring-pressed tension plat with shoes 145. The feed mechanism for the sensitive film is similar in construction but is reversible and has a smaller stroke; a friction drive may be applied alternatively to the spool 151 or the spool 153 so as to facilitate the production of " trick " pictures. The projection lens 263 is mounted in a sleeve 265 so that it is adjustable for focusing and may be held by a clamp 267. A usual fine adjustment for focusing 269 is provided, and the image on the film may be examined through a window 273 at the end of a tube 275. The light-tight magazines 155, 157 are connected to the casing P by dark-boxes 278. Each box has grooves 281, Fig. 27, and lips 295 within it which engage corresponding parts on the outside of the nose 277 of each magazine, the parts being so arranged that the magazines can only be secured in the relatively inverted position shown in Fig. 11. Each dark box has a slit for the passage of the film and one side hinged to the remainder of it so as to enable the magazine to be placed in it. The magazines have velvet strips 301, 303 secured at one end to each wall, and at the other end beneath a plate 305, passing between leaf springs 307, 309 which keep them together and prevent the entry of light to the magazine. Each magazine may be held in position by means of a plate 313 engaging a bracket 315.